Field of the Invention
The present invention relates generally to agricultural planters. In particular, the present invention relates to seed tube guards having a long wear life and an internal fluid channel for applying liquid into the bottom of the seed furrow.
Description of the Related Art
Conventional agricultural row crop planters have a plurality of planting row units attached to a transverse toolbar by a parallel linkage. Each row unit has a subframe to which is mounted a furrow opener for forming a seed planting furrow, depth control wheels for controlling the operating depth of the furrow opener, a seed meter for singulating and directing seed through a seed tube into the furrow, and a furrow closing assembly that follows behind the seed tube and furrow opener to close the furrow and thereby cover the seed with soil. A common type of furrow opener is a double disc assembly in which two opener discs contact each other at a leading edge and diverge at a small angle to form the seed planting furrow. The depth of the furrow is determined by the adjustable position of the depth control wheels.
A seed tube guard comprising a metal member is typically positioned in front of the seed tube between the double opener discs. A seed tube guide keeps the seed tube centered on the seed tube guard to prevent the seed tube from being displaced laterally and wearing against the rotating opener discs. Conventional seed tube guards are disclosed in U.S. Pat. Nos. 5,664,507 and 7,263,937.
During operation, ground pressure causes the opener discs to deflect inward until they contact the wear surfaces of the seed tube guard. The seed tube guard functions to protect the seed tube by maintaining a distance between the opener discs. The seed tube guard also helps create a more effective seed furrow by maintaining a proper distance between the opener discs.
It is generally known that most seed tube guards supplied as original equipment have a short wear life. This is due primarily to the inadequate wear resistance of the material and also the small wear surface.
A seed tube guard assembly with floating hardened wear plates is disclosed in U.S. Pat. No. 7,131,384.
A seed tube guard with liquid capability is described in U.S. Pat. No. 7,096,805. The liquid capability is provided by a stainless steel tube welded onto the leading surface of an OEM seed guard, which is made of a mild cast material. The liquid placement with this prior art seed tube guard has been found to reduce splatter inside the opener blades, but the seed tube guard itself still suffers from the problem that it wears too quickly.
A need still exists in the industry for an improved seed tube guard that is inexpensive to manufacture, provides a long operating life, and incorporates a fluid delivery channel for placing small amounts of liquid fertilizer or other fluids in the seed furrow.